Construction forms are known for molding poured concrete walls, floors, roofs and the like. When making walls, forms generally comprise a pair of spaced panels that define an outer surface of the walls and the forms are intended to be removed once the concrete is set. More recently, thermal properties of the walls has been given more consideration, as has the need to incorporate thermal insulation in the walls.
For example, U.S. Pat. No. 6,536,172 to Amend discusses an insulating wall form comprising a pair of panels made of polystyrene arranged in a spaced parallel relationship. Bridging ties span between and respective ends are embedded in the panels to hold the form shape during pouring of a concrete charge in between the panels. The bridging ties include retainer arms for securing reinforcement bars during pouring of the concrete. Once the concrete sets, a structurally sound wall results having thermal insulation on both of its sides. The bridging ties include T-shaped end plates that are embedded in the panels and act against the great weight of the wet concrete to prevent the insulating panels from being forced apart during pouring.
Such forms are generally sufficient for withstanding forces from wet concrete for walls of moderate thickness and height. However, when constructing walls having large heights and thicknesses, accordingly larger forces are being applied to the forms. It has been found that these larger forces are significant enough to split or otherwise deform the polystyrene form. In particular, force against the concrete-facing surface of the form tends to transmit tension to the outward facing surface, causing a split in the form. The wet concrete flows through the split, compromising the integrity of the wall and forcing the insulation apart. While other form materials may be used having physical properties that resist deformation, those same materials generally do not have the insulating properties of polystyrene or similar materials. While materials such as polystyrene are excellent for insulation because, they do not generally have physical properties ideal for resisting deformation or splitting due especially to tension.
Prior approaches to this problem involved applying additional, more frequently-spaced bridging ties. However, as would be understood, additional bridging ties consumes additional cost and labour time. Furthermore, with an increase in the number of bridging ties molded transversely into the concrete, it is possible that the strength of the concrete itself can be compromised.
Thermal insulation has also been recognised as beneficial for concrete floors and roofs. While pouring floors or roofs, the wet concrete is unable to support its own weight, since it has not yet bonded sufficiently for self-support and support of additional loads. Furthermore, prior art insulated concrete forms for floors and roofs made of polystyrene and similar materials do not have the structural integrity to receive great volumes of poured concrete. As such, supporting shoring or scaffolding is generally required every so many feet underneath the forms to support the weight. Even without the concrete, shoring is generally recommended to support the weight of construction workers walking overhead with spans more than a few feet. While thicker forms having greater resistance to splitting may be used, it is clear that the floor or roof must also be accordingly thicker. In some applications this is unacceptable as it decreases room volume etc.
The above-described problem with floor and roof forms has not been addressed in the art. For example, Insul-Deck of Florence, Ky., U.S.A. provide a concrete form for floors and roofs. Insul-Deck's forms are considered state of the art but still require extensive shoring during construction to maintain the weight of wet concrete prior to setting. Once the concrete has set, the shoring may be removed because the concrete bonds to support itself. Furring strips running the length of the form may be integrated with the form. However, due to the furring strips' relationship with the form, at best they marginally increase the weight-bearing ability of the form. As such, the furring strips are not sufficient in configuration for supporting the weight of poured concrete or even a construction worker for spans more than a few feet. In fact, depending on the method by which the furring strips have been integrated with the form, their presence may in fact weaken a form's weight-bearing ability, possibly necessitating further shoring underneath.
It is object of an aspect of the present invention to provide panels for forms for molding walls, floors, roofs and the like of concrete that address at least some of the above-described deficiencies.